Motor brake



Feb. 23, 1932. DEWANDRE 1,846,317

MOTOR BRAKE Original Filed March 13, 1924 Patented Feb. 23, 1932 UNITEDSTATES PATENT OFFICE ALBERT DIWANDBE, OF LIEGE, I BELGI'UI, ABSIGNOB'I'O SERVO-BIN SOCIE'IE ANONYME, OF LIEGE, BELGIUI DEWANDBE ROTOR BRAKEOriginal application filed larch 13, 1924, Serial No. 698,022, and inBelgium February 12, 1924. Divided and this application filed larch 4,1826, Serial No. 82,243. Renewed Kay 11, 1881.

This invention relates to motor brakes of that type in which the brakingforce is produced by the action of a artial vacuum induced by thesuction of t e engine as transmitted to a cylinder in which a brakeconnected piston is operated, and is a d1V1S10I1 of application, SerialNo. 699,022, filed March 13, 1924, patented October 19, 1926, No.1,603,750. 'Thecontrol of-the movement of the piston in the cylinder ismade b means of a distributor by which the cylin er is, at one side ofthe piston, placed in communication with the engine suction or with theatmosphere at will, or held in a predetermined position with both theatmospheric and suction communication cut oil.

Brakes of this type and controlled in this manner are described inPatent N 0. 1,539,166, issued to me on May 26, 1925, in which as well asin the present application the operating means is so arranged that theeifort for actuatingthe distributor increaseswith the brakingefiortexerted by the piston, so that the operator may know the extent ofbraking action by the efiort required on his part to maintain suchbraking condition.

The invention is illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view, more or less diagrammatic, illustratingone form of the" invention. 1 Figure 2 is a section through the lostmotion device of the form shown in Fi re 1.

Figure 3 is a view similar to Figure 1 illustrating a modifiedarrangement of parts.

. As previously stated, the distributor, control means therefor, andother details of the present invention are similar to such details asshown in Patent No. 1,603,750 issued to me on October 19, 1926, and suchsimilar details will be briefly referred to herein simply to illustratethe sequences of operation.

The motor mechanism includes a cylinder 3 in which operates a piston 4,the cylinder being open to atmos heric pressure on one side of thepiston an having pipe communication on the opposite side of the pistonwith the distributor, so that the cylinder on said latter side of thepiston may, through appropriate control oi the distributor, be opened tothe control of the suction of theengine, be vented to the atmosphere, orbe closed tagainst both the atmosphere and engine suc- 1011.

In the first mentioned control, the piston will move toward the left inFigure 1; in the second mentioned control the pressure on both sides ofthe piston will be balanced; and in the third mentioned control, thepiston will remain in the position induced by the suction, that is, bythe pressure differences at the time the cylinder is out off both fromthe suction and from the atmosphere. The first condition naturallyoperates to apply the brakes, the second condition operates to releasethe brakes, and the third condition operates to hold the brakes set inany predetermined braking relation.

The brake pedal 13 is connected by a rod 14 to a 10st motion devicewhich includes a cylindrical member 25 in which the end of rod 14 plays,the open end of the cylinder being closed by a removable closure and theend of rod 1 1 being provided with a disk 28 between which and theremovable closure for the cylinder there is placed a coil spring 27which normally tends to hold the disk 28 against the closed end ofcylinder 25.

The cylinder 25 is connected to the brake mechanism here indicatedat 6.There is thus a relative or lost motifirji between the cylinder 25connected to the brake mechanism and the rod 14 connected to the footlever 13. The distributor 'A includes a suction control valve a andatmospheric control valve 12, for controlling the suction admissionthrough the pipe 0 leading to'the cylinder 3, or the atmospheric vent (1through said pipe, a lever crfor actuating said valves, as described inthe patent above mentioned. The distributor is operated by a Bowden wireconnection including a sheath 23, one terminal of which is connected vtoa clip 23 secured to the rod 14' with the opposite end fixed to asupport 7' and a wire 23 freely movable in the sheath 23 and connectedat one end to an ear or lug 25 rigid with the cylinder part 25 of thelost motion connection, the I a valve operating lever e forming part ofthe distributor. f

Obviously, as the rod 14 moves toward the left responsive to manualoperation of the pedal 13, the sheath 23 is correspondingly moved,whereupon, as will be plain from the patent above mentioned, thenormally open atmospheric vent controlling valve b is closed and thenormally closed suction controllin valve a is opened. As the brakes areapplie the cylindrical member 25 moves forwardly or to the left inFigure 2, bringing the lug 25' closer to the clip 23 and again restoringthe relation of the sheath and wire of the Bowden connection to somedegree, with the result of permitting the suction valve previouslyopen'to close without, however, permitting a suflicient movement of thewire of the Bowden wire connection to permit or cause the atmos hericvent valve to open. I

The brake mechanism, here indicated 'at 6, is connected to the piston 4through the inedium of a cable made up of parts 5 and 5", one terminalof which is connected to the piston and through the use of a pivotedsector 39,

such cable is continued around an idle ulley 24 fixed to a convenientpart of the rame, thence around a pulley 22 carried in links 23 securedto the brake mechanism 6, and thence to the foot lever 13.

It is to be noted that the movement of the piston 4 responsive to theopening of the suction valve of the distributor will cause the cableparts 5 and 5 to exert a braking movement on the brake mechanism, suchof course operating against the fixed point at the foot pedal which isheld in operated position by the operator. As the brakes move inresponse to this cable operation, the parts of the lost motion deviceare caused to a preach the normal, with the result, as be ore described,of permitting the suction valve of the distributor to close without,however,

0 ening the atmosphericvent valve. The

piston 4 then remains under the pressure difierences occurring at thatmoment-and the brakes will remain set with that particular pressure. v

Itwill be Iafiparent that when the brakes are set the p of the piston onthe cable is exerted more or less directly on the foot pedal 13, thisparticular pull of the cable being of course in opposition to the manualinfluence on the pedal. The greater the pull of the piston on the cablethe greater will be the pressure of the brakes and the greater will bethe p ll of the cable on the foot pedal in oposition to the manualpressure thereon.

his pull on the foot pedal is therefore directly proportioned to thepower of the brake application and as this action on the pedal is inopposition to the manual influence thereon, such cable pull constituteswhat may be termed a reaction, distinctly and positively '1 apparent tothe operator and indicating by its extent the power with whichthe brakesare applied. That is-to say, the greater the power of brake applicationthe greater will be this reaction, and hence the o rator is at all timesadvised as to the bra ing power being exerted.

If, following any power application of the brakes, additional brakingforce is required,

additional pressure may be applied to the pedal 13 which will produce arepetition of the movement of the operating parts hereinbeforedescribed. This will obviously compel a further movement of the pistonand a corresponding increase in the power applied to the brakes. 1 If itis desired to relieve the brakes, the pedal 13 is permitted to return tonormal position, this movement being assisted by the reaction or pull onthe cable previously referred to. In this movement of the pedal, theclip 23" moves toward the cylinder 25 under the action of spring 27assisted by the reactive force of the cable acting on the pedal 13 andthrough the rod I i This relative ovement of the clip 23 causes thesheath terminal 23 of the Bowden wire connection to approach the lug 25'and thereby operate the distributor to open the atmospheric vent valve 6and vent the cylinder 3 to the point where the pressure on the piston isbalanced. In this movement the spring 27 tends to return to normalposition without materially afiecting the release of the braking action.In addition, the reflex or reactive action due to the connection of thecable also assists to bring the parts to this position for effecting therelease of the brakes. Following the almospheric balance of the piston,the brakes return to inoperative position incident to the ordinaryrelief springs rovided in brakes of this character, and in t is movementtend to move the cylinder 25 to the right, restorin the lost motionconnection parts to norma position and maintaining the distributorvalves in normal position, that is with the atmospheric vent valve 1)open and the suction valve a closed.

In the form of the invention illustrated in Figure 3, the cylinder 3,piston 4 and brake mechanism 6", together with the distributor,

are designed to be substantially identical with the similar parts in theform shown in Fig ure 1; The lost motion connection used in the formshown in Figure l is materially modified in the form shown in Figure 3,here comprising an auxiliary foot lever or supplemental control lever 43p'ivotally supported at 40 on a fixed part of the vehicle and having anangle arm 43 to which thebrake mechanism 6 is connected by a rod 6.

Themain foot or control lever 13, is pivotally supported at 13' on thesupplemental control lever 43 above the pivotal mounting of the latter,and the Bowden wire connection providing the lost motion control is tillconnected to these respective control levers, the sheath 12' beingconnected to the main control lever 13 and the wire 12 being connectedto the supplemental control lever 43. The levers 13 and 43 have aflexible connection such as a spring shown at 43 to permit limited,relatively free movement of the respective levers.

An auxiliary lever 40 is pivotally sup ported at 40 substantially inline with and close to the pivot of the supplemental lever 43 below thepivotal support of the lever 13, the upper end of the lever 40underlying the heel of the lever 13 below the pivot 13' and the lowerend of lever 40 being con-- nected to the operating cable in a manner tobe later described. The supplemental lever 43 depends below its pivot 40and carries a rod 41 adjustable in such lower end, which rod supports apulley 41.

An idler pulley 42 is connected by a hanger 42 to a fixed part of thevehicle. An operating cable made up in two parts, one part 5 of which isconnected to the piston 4 and to a sector 39 mounted for pivotalmovement and in turn connected by the other cable part 5" which extendsaround pulley 41, thence around pulley 42 and terminally connected tothe lower end of lever. 40.

In applying the brakes, manual operation on the main control lever 13obviously shifts the sheath 12 of the Bowden wire'connection relativeto. the wire 12 of such connection, thus inducing the hereinbeforedescribed operation of the distributor wherein the atmospheric ventvalve is first closed and the suction valve opened. As the piston 4moves to the left in Figure 3 in response to the reduction of pressureon one side of the piston incident to the suction, the cable 5 isoperated; that is to say, that length of the cable between the pistonandsector is drawn to the left and the end of the cable connected to theremaining portion of the sector is drawn to the right, causing thatterminal of the cable connected to the lever 40 to be drawn to theright. Obviously, as the lever 40 is held from pivotal movement in theparticular direction by reason of the fact that its up per end underliesthe heel of the main control lever 13 now held by manual pressure,

the described movement of the cable tends to draw the pulley 41 andthereby the lower end of the auxiliarv or su plemental control lever 43to the right. This swings the angle arm 43 to the left and throughthe'rod 6 and brake rodding 6 applies the brakes. Si multaneously withthis movement, the upper end of the lever 43 is moved to the left,moving the wire 12 of the Bowden wire con nection to control thedistributor to permit the closing cat the suction valve without openingthe atmospheric vent valve, whereby the brakes are held in their thenapplied positions. @bviously, if further braking power is desired, themain control lever 13 is moved farther in the initial direction,resultin 1n duplication of the operation just described and of coursemoving the piston 4 to a greater extent and applying additional force tothe brakes.

It is to be noted that the pull exerted on the cable parts 5 and 5 isdirected through the lever 40, this lever being, however, heldsubstantially immovable in the direction of cable pull by reason of thefact that it underlies the manually held main control lever 13. However,this cable pull is transmitted through the lever 40 to the manualcontrol lever 13 in opposition to the manual influence thereon, and thisso transmitted cable pull is directly proportional to the power exertedon the brake mechanism. Therefore, a reflexaction on the brake power istransmitted to the operator who is thus at all times in a position todetermine the extent of brake application through this resistance to hismanual pressure incident to the reflex action described.

The release of manual pressure on the main control lever 13 and thespring and cable reaction operates the Bowden wire in a manner to openthe atmospheric vent valve of the distributor, admitting a pressurebalance to the piston 4 and permitting the cable to relieve its pullonthe supplemental control lever 43 and thereby release the brakes.Obviously, the brakesmay be directly applied by manual pressure throughdirect operation transmit corresponding movement to the brakes and exerta reaction on the manuallyoperable element.

2. In a brake system for motor vehicles, the combination of a cylinder,a piston therein responsive to pressure differences, brakes, amanually-operable element, a distributor operative through the relativepositions of the brakes and manually-operable element for controllingthe pressure difierences on the piston, and flexible connectorsterminally connected to said piston and to said manually-operableelement, said connectors being arranged to exert a moving influence onthe brakes when the piston is operated by the pressure difi'erences andthe manually-operable element is held.

3. In a brake system for automobiles, a and piston, said cablesoperating the brake cylinder, a piston therein subjectedto presmechanismin the movement of the piston sure differences, brakes, a manual controlunder said pressure difierences.

element, a distributor operative in the relative positions of the brakesand manual control element to control said pressure difierences cablesterminally connected to the piston and to the manual control element,means wherebya pull exerted on the cables will operate said brakes, saidmeans permitting the pull of the cables to be directly transmitted tothe manual control element to exert thereon a reaction to manualinfluence proportioned to the pull of the cables and thereforeto thepowerapplication of the brakes.

4. In a brake system for automobiles, a cylinder, a piston thereinsubjected to pressure differences, brakes, a manual control element, adistributor operative in the relative positions of the brakes and manualcontrol element to control said pressure differences, cables terminallyconnected to the piston and to the manual control element, means withwhich the cables cooperate intermediate their terminals whereby a pullexerted on the cables will operate said brakes, said means permittingthe pull of the cables to be directly transmitted to the manual controlelement to exert thereon a reaction to manual influence proportioned tothe pull of the cables and therefore to the power-application of thebrakes.

' 5. In a brake system for motor vehicles, the combination with brakemechanism, of a brake cylinder, a'piston in said cylinder subjected topressure difierences, a control lever and a cable connection arrangedbetween the piston, the brake mechanism and said control lever, wherebyto set the brake mechanism upon operation of the pistonandsimultaneously exert on the control lever a reaction which is afraction of the pressure of the brake mechanism.

6. In a brake system for motor vehicles, the combination with brakemechanism, of a brake cylinder, a piston in said cylinder subjected topressure differences, a control lever and cables arranged between thepiston, the

brake mechanism and said control lever,

whereby to set the brake mechanism upon operation of the piston andsimultaneously .exert on the control lever a reaction which is afraction of the pressure ofthe brake mech-' anism, said cables beingterminally connected to the control lever and to the piston and having aconnection with the brake mechanism.

. In a brake system for motor vehicles,

the combination with brake mechanism, of a brake cylinder, a piston insaid cylinder subjected to pressure differences, a control lever, a lostmotion connection between said control lever and brake mechanism, saidlost motion connection serving to operate the brake mechani'smdirectlyfrom the control lever following a predetermined movement of the controllever, and cables between the control lever In testimony whereof I aflixmy signature.

ALBERT DEWANDRE.

